Emaxuel foebstee



(N0 Model.)

B. POBRSTBR.

STONE SAWING MACHINE.

Y No. 350,191. l Paocn. 5, 1886.

m By

A fron/VH1? UNITED STATES PATENT Ormes.

'EMANUEL FOEDSTER, OF NFV YORK, N. Y.

STONE-SAWING MACHINE.

SPECIFICATION forming part of Letters Patent No. 350,191, dated October 5, 188C.

Serial No. 197,272. (No model.)

T0 all whom it may concern:

Be it known that l, EMANUEL FonRs'rnR, a resident of New York city, in the county and State of New York, have invented an Improved Stone-Sewing Machine, of which the following is a full, clear, and exact description, reference being made to the accompanying drawings, in which- Figure l represents a face view, partly in section, of my improved stone-sawing machine, and Fig. 2 is a detail cross-section of the saw-blade.

This invention has for its object to improve the construction of the reciprocating sawblade which is used in machinery for cutting stone, the invention being applicable to the kind of blade which cutswit-h the aid of sand, shot, or the like.

The invention consists, principally, in inaking the upper part of the blade ot' three or more thicknesses of inetal, the outer thicknesses being of steel or other hard substance and the central thickness ot.' soft .niet al. \Vith this blade is combined a lower rotating twisted bar, which, as the bladeto which it is attached is reciprocated, is revolved to agitatethe sand or shot by which the cutting is done, all as here inafter more fully described.

In the drawings, the letter A represents the upper part or body of the cuttingblade, `which is made of three or more thicknesses, a a and b, of niet-al, the outer thicknesses, a a, being ot steel or other hard substance, and the central thickness or thicknesses, Z, ot' softer metal-such as iron.

B is the lower part ol' the blade, which is a bar ot' twisted iron or steel, and hung in straps (I, that connect it with a nut, .1'. The bar B is twisted so as to form short spiral convo] nti o ns, as is clearly indicated in the drawings, and carries at its ends bevel gear-wheels e, that mesh into bevel-pinionsf, which are supported by upright shafts C C, thathave their bearings in the frame D, which carries the blade A B. The upper ends of the shaft C have toothed wheels g, that mesh into stationary racks h,

which are supported by the fixed frame-work- E of the machine.

The sliding frame D has rollers fi, which support it on the stationary rails j. A pitman, F, from a driving-shaft connects with the frame D, to reciprocate it on the rails j. Vhile the frame D is reciprocatcd the toothed wheels g are revolved and transmit rotary motion to the twisted bar B, which forms the lower part ot' the blade.

Asthe blade descends into the stone to be cut, bythe means hereinafter stated, the twisted bar B remains in gear with the bevel-pinionsf, by reason of their being arranged to slide on the shafts C-that is to say, cach pinionj' is free to slide on its shaft C, but connected thereto by feather and groove, so as to be revolved by the same.

I have shown each end ol the twisted bar B to be geared into a shaft C; but the ends ot' iny invention will be attained if only one such connection be established sufficient to cause rotation of the twisted bar B.

The blade A B is suspended in the reciproA eating frame D l'roln upright screws 7.', which carry bevel-pinions m at their upper ends in gear with similar pi nions on a horizontal shalt, H. lVhenever this shaft 1I is turned, by hand or automatically, the screws f will be turned to feed the cutting-blade A B down during the progress of the work.

The twisted bar B is coiled in such a fashion as to be wider than the blade A above it, so that, as is shown in Fig. 2, the blade A will never be in contact with the stone. The twisted bar B serves to agitate and move about the particles of sand or shot which are to perform the cutting operation. The twisting of the bar B serves to keep the particles of sand or shot constantly in, action, and to therefore present new cutting-surfaces continuously to the stone.

By making the central` thickness or thicknesses of the blade A of substantially soft substance I prevent the particles of sand or shot front being carried by the twisted bar into the space between said bar and the blade A- that is to say, the lower edges ol" the steel blades a are notched, as shown in Fig. l., to ft the spiral form ot' the rotating bar B, so that sand or shot cannot get between the parts A and B.

The soft-metal central portion, b, ofthe blade A will allow the twisted bar B to form a convenient groove in the lower part ofA, in which the upper part of B can revolve.

IOO

/Vhen I mention in this specification a reciprocating blade7 I mean one which reciprocates in the act of cutting the stone, and do not mean that the said blade should not also have an up-and-down motion at the end of cach stroke.

Nothing herein contained is intended to claim means for reciprocating the blade-car rying frame D, nor the character 0i' the motion Which the saine receives.

Vhat I claim isl. The stone-cutting blade constructed of the upper part, A, having cheelzpieces a a and middle piece, b, and lower twisted bar, B, the piece b being of softer metal than the pieces a, substantially as herein shown and described.

EMANUEL FOERSTER.

Vituesses:

CHARLEs G. M. THOMAS, HARRY M. TURN. 

